a 3000-km impact range. The IIP trace obtained for one of the SLV3 flights using both LKF and QDF is given in Fig. 2, which clearly shows the better performance of the LKF. Additionally, an assessment of radar noise could be made by determining the deviation of the real measurements against the estimated measurements. Further, the editing of wild measurements by comparing the residuals with their variances helped to identify radar malfunction in real time. In fact, the LKF outperforms for real flight data with good model compensation and noise suppression.